Tag Archives: calendar
EU Vote Bursts Bubble On Biofuel Future
DARAGH MCCULLOUGH – 29 AUGUST 2013 A recent vote by EU politicians makes the future of the nascent biofuel sector here even more precarious than it already was. A decade ago we were told that the world had entered a new post-peak oil era. With dwindling supplies, countries needed to take action to secure new sustainable sources of energy. Ireland was as good a case for bioenergy as anywhere, spending €6bn annually on imported energy. Everybody wanted a slice of that action. So ambitious targets obliging us to have 20pc of our total energy requirements coming from renewable sources by 2020 were signed into law. The Government pumped millions into schemes to incentivise farmers to grow new biomass crops such as elephant grass and put up oil-pressing plants. To the delight of the sceptics, much of this endeavour appears to be unravelling at the seams. Yes, wind-farms continue to be constructed and solar-panels adorn more and more roof-tops. But hundreds of acres of elephant grass, or ‘miscanthus’ to give it its proper name, have already been ploughed in by disillusioned farmers. The more enterprising individuals that invested millions in briquetting and oil-pressing plants have lost their shirts on the enterprises as market reality kicked in. Fossil fuels are becoming more expensive, but we are becoming more efficient at using them and extracting them. The actual end-game in terms of supplies is still so far off that the market still doesn’t price it into the equation. Irish farmers discovered to their cost that the rest of the planet is also able to generate masses of biomass – and ship it in here at a fraction of the cost that the Irish farmer needs to make a profit. Waste by-products such as palm kernals and cocoa shells are available for virtually nothing. The countries that produce these often can’t produce beef or milk at the same cost that we can in Ireland. Farmers and policymakers momentarily lost sight of what they had – a real competitive advantage in producing. At the same time, policymakers are still confused as to whether growing crops to fuel our cars actually makes sense. As a result, after their initial wave of enthusiasm, European politicians are slowing coming around to the idea that promoting the production of biomass and biofuels may not be the best use of our taxes. “Biofuels increase the demand for crops, which can encourage, at a global level, putting land into production, land that might not otherwise be used. And greater demand can lead to higher prices for food, hitting the poor hardest,” said Ireland East MEP Mairead McGuinness . As a result the EU recently voted to cap the amount of biofuel that can come from food sources at 5.5pc. But experts in Teagasc still believe that there is a future in the sector for those willing to take the risk. “We had to start somewhere in our search for alternatives to fossil fuels,” said renewable energy specialist Barry Caslin. “Growing miscanthus and oilseed rape crops to simply burn for heat is first generation stuff. Algae, waste digesters and enzymes are part of the second generation, and at some point we will be growing fuel in sustainable ways that is competitive with fossil fuels,” he said. In the meantime, Mr Caslin believes that Ireland is losing out on investment, jobs and economic growth if the Government doesn’t continue to support the advancement of the sector. It’s a classic case of the chicken and egg. Should we continue subsidising the development of renewable energy sources or should we wait until the market can support the development of the sector itself? Time will tell. Irish Independent Continue reading
Power From Wood, Wood-Derived Fuels Up In June
Taylor Scott International News Taylor Scott International Taylor Scott International, Taylor Scott Continue reading
Rapid And Effective Oxidative Pretreatment Of Woody Biomass At Mild Reaction Conditions And Low Oxidant Loadings
One route for producing cellulosic biofuels is by the fermentation of lignocellulose-derived sugars generated from a pretreatment that can be effectively coupled with an enzymatic hydrolysis of the plant cell wall. While woody biomass exhibits a number of positive agronomic and logistical attributes, these feedstocks are significantly more recalcitrant to chemical pretreatments than herbaceous feedstocks, requiring higher chemical and energy inputs to achieve high sugar yields from enzymatic hydrolysis. We previously discovered that alkaline hydrogen peroxide (AHP) pretreatment catalyzed by copper(II) 2,2 -bipyridine complexes significantly improves subsequent enzymatic glucose and xylose release from hybrid poplar heartwood and sapwood relative to uncatalyzed AHP pretreatment at modest reaction conditions (room temperature and atmospheric pressure). In the present work, the reaction conditions for this catalyzed AHP pretreatment were investigated in more detail with the aim of better characterizing the relationship between pretreatment conditions and subsequent enzymatic sugar release. Results: We found that for a wide range of pretreatment conditions, the catalyzed pretreatment resulted in significantly higher glucose and xylose enzymatic hydrolysis yields (as high as 80% for both glucose and xylose) relative to uncatalyzed pretreatment (up to 40% for glucose and 50% for xylose). We identified that the extent of improvement in glucan and xylan yield using this catalyzed pretreatment approach was a function of pretreatment conditions that included H2O2 loading on biomass, catalyst concentration, solids concentration, and pretreatment duration. Based on these results, several important improvements inpretreatment and hydrolysis conditions were identified that may have a positive economic impact for a process employing a catalyzed oxidative pretreatment. These improvements include identifying that: (1) substantially lower H2O2 loadings can be used that may result in up to a 50-65% decrease in H2O2 application (from 100 mg H2O2/g biomass to 35–50 mg/g) with only minor losses in glucose and xylose yield, (2) a 60% decrease in the catalyst concentration from 5.0 mM to 2.0 mM (corresponding to a catalyst loading of 25 mumol/g biomass to 10 mumol/g biomass) can be achieved without a subsequent loss in glucose yield, (3) an order of magnitude improvement in the time required for pretreatment (minutes versus hours or days) can be realized using the catalyzed pretreatment approach, and (4) enzyme dosage can be reduced to less than 30 mg protein / g glucan and potentially further with only minor losses in glucose and xylose yields. In addition, we established that the reaction rate is improved in both catalyzed and uncatalyzed AHP pretreatment by increased solids concentrations. Conclusions: This work explored the relationship between reaction conditions impacting a catalyzed oxidative pretreatment of woody biomass and identified that significant decreases in the H2O2, catalyst, and enzyme loading on the biomass as well as decreases in the pretreatment time could be realized with only minor losses in the subsequent sugar released enzymatically. Together these changes would have positive implications for the economics of a process based on this pretreatment approach. Author: Zhenglun LiCharles H ChenEric L HeggDavid B Hodge Credits/Source: Biotechnology for Biofuels 2013, 6:119 Continue reading
